<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>易错点</title>
</head>
<body>
    <div class="main"></div>
</body>

<style>
    /**媒体查询建议都小到大顺序书写**/
    /**媒体查询不出现><=符号使用:**/
    /** and 后面的空格不能省去**/
    body{
        margin: 0;
    }
    @media screen and (min-width:375px){
        .main{
            width:375px;
            height:200px;
            background-color: aqua;
        }
    }
</style>
</html>